Abstract
A strain of SV 41 given by R. M. Chanock was grown and passaged in Vero cells (Cercopithecus kidney cell line). In the reciprocal cross neutralization tests among Paramyxoviruses SV 41 was clearly distinguished from other viruses except that slight crossing was observed against CA virus. Some physico-chemical tests, including size determination by filtration, sensitivity to chloroform and nucleic acid typing using IUDR, and some host range tests gave results essentially consistent with those described originally by Miller et al. on primary culture-grown viruses. Contrary to our expectation in the heating tests at 50°C SV 41 was not labile; that is, after heating for 9 hours a decline of infectivity by 5 logs was demonstrated but still left 1.5 log of infectivity.
Search for serum neutralizing antibodies in humans, monkeys and various experimental and domestic animals revealed that the sole species which gave positive results was humans and no positives were encountered in 321 monkeys including Cynomolgus, Rhesus and Cercopithecus species which were imported from 1960 to 1966 and kept for varying periods of time in this laboratory, Whether the SV 41 antibodies in humans are due to infections of SV 41 itself or not can not be decided from our present data. Its confirmation waits for future investigations.
